scholarly journals Monitoring the use of road-crossing structures by arboreal marsupials: insights gained from motion-triggered cameras and passive integrated transponder (PIT) tags

2015 ◽  
Vol 42 (3) ◽  
pp. 241 ◽  
Author(s):  
Kylie Soanes ◽  
Peter A. Vesk ◽  
Rodney van der Ree

Context Wildlife crossing structures are installed to mitigate the impacts of roads on animal populations, yet little is known about some aspects of their success. Many studies have monitored the use of structures by wildlife, but studies that also incorporate individual identification methods can offer additional insights into their effectiveness. Aims We monitored the use of wildlife crossing structures by arboreal marsupials along the Hume Freeway in south-eastern Australia to (1) determine the species using these structures and their frequency of crossing, (2) determine the number and demographic characteristics of individuals crossing, and (3) use the rate of crossing by individuals to infer the types of movement that occurred. Methods We used motion-triggered cameras to monitor five canopy bridges and 15 glider pole arrays installed at 13 sites along the Hume Freeway. The five canopy bridges were also monitored with passive integrated transponder (PIT)-tag readers to identify the rate of use by individuals. Key results Five species of arboreal marsupial were detected using canopy bridges and glider poles at 11 sites. Our analysis suggested that increasing the number and the distance between poles in a glider pole array reduced the rate of use by squirrel gliders. The PIT tag and camera footage revealed that the structures were used by adult males, adult females and juveniles, suggesting that all demographic groups are capable of using canopy bridges and glider poles. At two canopy bridges, multiple squirrel gliders and common brushtail possums crossed more than once per night. Conclusions Given that previous studies have shown that the freeway is a barrier to movement, and that many of the species detected crossing are subject to road mortality, we conclude that canopy bridges and glider poles benefit arboreal marsupials by providing safe access to resources that would otherwise be inaccessible. Implications Although the factors influencing crossing rate require further study, our analysis suggests that glider pole arrays with fewer poles placed closer together are likely to be more successful for squirrel gliders. The individual identification methods applied here offer insights that are not possible from measuring the rate of use alone and should be adopted in future monitoring studies.


2017 ◽  
Vol 39 (2) ◽  
pp. 254 ◽  
Author(s):  
Kylie Soanes ◽  
Briony Mitchell ◽  
Rodney van der Ree

We review eight years of monitoring data to quantify the number of predation attempts on arboreal marsupials using canopy bridges and glider poles across a major road in south-east Australia. We recorded 13 488 detections of arboreal marsupials on the structures, yet only a single (and unsuccessful) predation attempt was recorded.



2021 ◽  
Vol 13 (2) ◽  
pp. 675
Author(s):  
Hyunjin Seo ◽  
Chulhyun Choi ◽  
Kyeongjun Lee ◽  
Donggul Woo

Roads are notable and responsible for the loss of biodiversity and disruption of wildlife habitats connectivity. Wildlife crossing structures (WCS) help wildlife move between habitats by connecting fragmented habitats. Their effectiveness is affected by various factors. Here, to identify methods for improving the effectiveness of wildlife crossing structures, we controlled the effect of intrinsic factors, such as size, that are difficult to improve in an already installed area, and then, evaluated the differences in extrinsic factors using 12 landscape characteristics. Our results show that 18 wildlife crossing structures were selected with propensity-score (PS) matching method. The surrounding landscape characteristics differed between high-effectiveness wildlife crossing structures and low-effectiveness wildlife crossing structures. Particularly, there was a significant difference between the ‘statutory protected area’ and the ‘edge’ index of the morphological spatial pattern analysis among the landscape characteristic variables derived within 1 km2 of wildlife crossing structures. We empirically demonstrate that characteristics around highly effective WCS, statutory protected areas are widely distributed, and the ratio of edge of MSPA is low (within 1 km2). Therefore, an important outcome of our research is the demonstration that management of WCS itself is important, but conservation of surrounding habitats and landscape management plans are also significant.



2021 ◽  
Vol 130 ◽  
pp. 108110
Author(s):  
Lindsey S. Roberts ◽  
Abigail B. Feuka ◽  
Erin Muths ◽  
Bennett M. Hardy ◽  
Larissa L. Bailey


2021 ◽  
Author(s):  
Jan Olof Helldin

Crossing structures for large wildlife are increasingly being constructed at major roads and railways in many countries, and current guidelines for wildlife mitigation at linear infrastructures tend to advocate for large crossing structures sited at major movement corridors for the target species. The concept of movement corridors has however been challenged, and pinching animal movements into bottlenecks entail risks. In this paper, I address the SLOSS dilemma of road ecology, i.e., the discussion whether a Single Large Or Several Small crossing structures along a linear barrier would produce the most benefit for wildlife. I point out risks, ecological as well as practical, with investing in one large crossing structure, and list a number of situations where it may be more beneficial to distribute the conservation efforts in the landscape by constructing several smaller crossing structures; for example when the ecological knowledge is insufficient, when animal interactions are expected to be significant, when the landscape changes over time, or when future human development cannot be controlled. I argue that such situations are often what infrastructure planning faces, and that the default strategy therefore should be to distribute rather than to concentrate passage opportunities along major transport infrastructures. I suggest that distributing passage opportunities over several smaller crossing structures would convey a risk diversification, and that this strategy could facilitate the planning of wildlife mitigation. What to choose would however depend on, i.a., landscape composition and ecology, and on relationships among target species. A single large should be selected where it is likely that it can serve a large proportion of target animals, and where the long-term functionality of the crossing structure can be guaranteed. I illustrate how species and regional differences may influence the choice, using the case of ungulates in Sweden. New research is needed to support trade-offs between size and number of crossing structures. Cost-effectiveness analyses of wildlife crossing structures are currently rare and need to be further explored. Camera trapping and video surveillance of crossing structures provide opportunities to analyze details concerning, for example, any individual biases according to sex, age, status and grouping, and any antagonism between species and individuals. Wildlife ecology research need to better address questions posed by road and railway planning regarding the importance of specific movement routes and movement distances.



2015 ◽  
pp. 184-189
Author(s):  
Rodney van der Ree ◽  
Edgar A. van der Grift


2015 ◽  
pp. 119-128 ◽  
Author(s):  
Edgar A. van der Grift ◽  
Rodney van der Ree


2011 ◽  
pp. 163-254
Author(s):  
Daijin Kim ◽  
Jaewon Sung

In the modern life, the need for personal security and access control is becoming an important issue. Biometrics is the technology which is expected to replace traditional authentication methods that are easily stolen, forgotten and duplicated. Fingerprints, face, iris, and voiceprints are commonly used biometric features. Among these features, face provides a more direct, friendly and convenient identification method and is more acceptable compared with the individual identification methods of other biometrics features. Thus, face recognition is one of the most important parts in biometrics.



2020 ◽  
Vol 7 ◽  
Author(s):  
Vincent Raoult ◽  
Clive N. Trueman ◽  
Kelsey M. Kingsbury ◽  
Bronwyn M. Gillanders ◽  
Matt K. Broadhurst ◽  
...  

Determining the geographic range of widely dispersed or migratory marine organisms is notoriously difficult, often requiring considerable costs and typically extensive tagging or exploration programs. While these approaches are accurate and can reveal important information on the species, they are usually conducted on only a small number of individuals and can take years to produce relevant results, so alternative approaches may be preferable. The presence of latitudinal gradients in stable carbon isotope compositions of marine phytoplankton offers a means to quickly determine likely geographic population ranges of species that rely on productivity from these resources. Across sufficiently large spatial and temporal scales, the stable carbon isotopes of large coastal or pelagic marine species should reflect broad geographic patterns of resource use, and could be used to infer geographic ranges of marine populations. Using two methods, one based on a global mechanistic model and the other on targeted low-cost latitudinal sampling of fishes, we demonstrate and compare these stable isotope approaches to determine the core population geography of an apex predator, the great hammerhead (Sphyrna mokarran). Both methods indicated similar geographic ranges and suggested that S. mokarran recorded in south-eastern Australia are likely to be from more northern Australian waters. These approaches could be replicated in other areas where coastlines span predictable geographic gradients in isotope values and be used to determine the core population geography of highly mobile species to inform management decisions.



2017 ◽  
Vol 65 (6) ◽  
pp. 362
Author(s):  
Francesca Lyndon-Gee ◽  
Joanna Sumner ◽  
Yang Hu ◽  
Claudio Ciofi ◽  
Tim S. Jessop

Rotational logging practices are used with the goal of reducing forest disturbance impacts on biodiversity. However, it is poorly understood whether such forest management practices conserve the demographic and genetic composition of animal populations across logged landscapes. Here we investigated whether rotational logging practices alter patterns of landscape-scale population abundance and genetic diversity of a forest-dwelling lizard (Eulamprus heatwolei) in south-eastern Australia. We sampled lizards (n = 407) at up to 48 sites across a chronosequence of logging disturbance intervals (<10 to >60 years after logging) to assess site-specific population changes and genetic diversity parameters. Lizard abundances exhibited a significant curvilinear response to time since logging, with decreased numbers following logging (<10 years), increased abundance as the forest regenerated (10–20 years), before decreasing again in older regenerated forest sites (>30 years). Lizard genetic diversity parameters were not significantly influenced by logging disturbance. These results suggest that logging practices, whilst inducing short-term changes to population abundance, had no measurable effects on the landscape-scale genetic diversity of E. heatwolei. These results are important as they demonstrate the value of monitoring for evaluating forest management efficacy, and the use of different population-level markers to make stronger inference about the potential impacts of logging activities.



2009 ◽  
Vol 31 (2) ◽  
pp. 89 ◽  
Author(s):  
Ian F. Hayes ◽  
Ross L. Goldingay

The vast network of roads around the world has had a significant effect on wildlife and ecosystems through habitat fragmentation, reduced dispersal and mortality by collision with vehicles. Road agencies worldwide now frequently install dedicated structures to facilitate the safe crossing of roads by wildlife. We conducted surveys to determine the use of dedicated wildlife overpasses and nearby underpasses at two locations on the Pacific Highway in north-eastern New South Wales. Road-kill surveys were conducted to provide some understanding of the species commonly killed and whether the rate of road-kill was lower at one location where crossing-structures were located. Use of the crossing-structures by wildlife was monitored with sand-transects. The most frequent users were macropods, bandicoots and rodents. Macropods made greater use of overpasses (n = 104 tracks) than underpasses (n = 36), whereas underpasses were used more by bandicoots (n = 87) and rodents (n = 82) than were overpasses (n = 28, n = 15, respectively). We identified 78 road-kills of 21 species on two sections of the Pacific Highway over a 7-week period. Bandicoots (n = 16) and macropods (n = 9) were the most frequently observed victims. The mortality of wildlife was lower along the highway section with the crossing-structures (0.04 road-kills km–1) than it was along the highway section without structures (0.15 road-kills km–1). The lack of replication precludes any firm conclusion that the crossing-structures reduced road mortality but the high level of use of the crossing-structures by species that were common victims of road-kill suggests an influence.



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